A study of a chiral 4-substituted oxazolidin-2-one in asymmetric transformations via soluble polymer-supported synthesis and fluorous synthesis

Abstract

Chiral auxiliaries remain one of the most reliable ways of generating new chiral molecules in a highly enantiomerically enriched form. We have synthesized a new chiral -substituted oxazolidin-2-one from ' L'-tyrosine via a novel method. The potential of this methodology has been established. Supporting a chiral auxiliary on a polymer provides a convenient work-up and purification procedure and makes its recovery simple. Careful choice of polymer and auxiliary is essential for its success. The first synthesis of a soluble polymer-supported oxazolidinone from the tyrosine-derived oxazolidin-2-one and the soluble poly(ethylene glycol)-monomethyl ether (MeOPEG) has been described. The behavior of the MeOPEG-supported oxazolidin-2-one in the asymmetric alkylation and the Diels-Alder reaction has been disclosed. Fluorous synthesis introduces an alternative route to traditional and polymer-supported synthesis. The synthesis of a novel, highly fluorinated silyl fluorous tag has been described. The tyrosine-derivedoxazolidin-2-one has been rendered fluorous upon attachment to the fluorous tag. Asymmetric aldol condensation of the fluorous-tagged oxazolidin-2-one has produced all four diastereoisomers and their stereochemical assignments have been confirmed. This is the first demonstration of the suitability of fluorous synthesis strategy for asymmetric synthesis of chiral oxazolidinones.